+
Related Flashcards
Related Topics
Cards In This Set
| Front | Back |
|
How long will muscle contraction last without regenerating ATP?
|
Only enough ATP reserve to sustain short contraction (2 seconds).15 billion thick filaments per fiber, at least 1000s of fibers per muscle. 2500 ATP per second per thick filament.
|
|
What are the 3 ways to replenish/generate ATP?
|
(1) Creatine Phosphate (CP) Reserves: ATP + Creatine --via creatine kinase--> ADP + CP. Creatine phosphate is a small molecule made from fragments of amino acids. Acquired through diet (or tablets but tablets could cause damage to liver and kidneys). Muscle contraction is limited. Lasts another 15 seconds.(2) Anaerobic Metabolism (Glycolysis): Lactic Acid<-----Pyruvate---->Glucose<----Glycogen. Primary source of ATP during times of peak activity. Does not require oxygen--Inefficient (2 ATP/Glucose): In cytoplasm, lactic acid fermentation. Keeps muscles going for another 2 minutes. Produces lactic acid--rapid muscle fatigue (lower pH).(3) Aerobic Metabolism: CO2 + H2O<----Pyruvate<------Glucose<-----Glycogen. Primary source of ATP during rest (95% of ATP): In mitochondria (requires oxygen). Fatty acids to generate ATP at rest--Glucose during moderate activity. Efficient--34 ATP per glucose.
|
|
Describe energy use at rest
|
Aerobic metabolism. Low demand for ATP. Fuel mostly fatty acids. Build glycogen/creatine phosphate reserves.
|
|
Describe energy use at moderate activity (such as a light jog)
|
Demand for ATP increases> O2 supply sufficient. Fuel mostly glycogen. No surplus ATP.
|
|
Describe energy use at peak activity (such as sprinting)
|
Anaerobic metabolism> O2 supply not sufficient. Most ATP from glycolysis. Fuel mostly glycogen.
|
|
What is Muscle Fatigue? What 4 factors are associated with muscle fatigue?
|
Fibers lose ability to contract despite neural stimulation. (1) Depletion of metabolic reserves within muscle fiber.(2) Damage to cell--Sarcolemma + Sarcoplasmic reticulum(3) Lowered pH--Ca++/troponin, Enzyme activity.(4) Reduced desire for activity--Low blood pH--Pain.
|
|
What happens during moderate intensity activity?
|
Energy reserves depleted. Glycogen, lipids, proteins.
|
|
What happens during high intensity activity?
|
Lactic acid accumulation. Tissue pH lowered, Enzyme function effected.
|
|
What 4 things are required for normal muscle function?
|
(1) Intracellular energy reserves (creatine phosphate, glycolysis). (2) Normal circulatory supply (glucose, fatty acids, oxygen). (3) Normal blood oxygen levels. (4) Blood pH in normal limits.
|
|
What are "True Cramps"?
|
Involuntary temporary strong muscle contraction. Caused by injury, fatigue, hyperexcitability of the nerves, dehydration or sodium loss, low calcium or magnesium (increased excitability of nerve endings), low potassium (also muscle weakness).
|
|
What contributes to Delayed-Onset Muscle Soreness?
|
Highest when eccentric contractions (muscle lengthens). Caused by damage to muscle cells and possibly muscle spasms.
|
|
What contributes to Short-Term Muscle Soreness?
|
Muscle fatigue.
|
|
What is the Recovery Period? What are the 3 steps of the Recovery Period? What is Oxygen Debt?
|
Return of muscle fibers to pre-exertion conditions. (1) Lactic Acid removed: Lactic Acid---->Pyruvate (liver), Pyruvate--->ATP, Glucose, Glucose--->Glycogen (muscle fibers). (2) Oxygen required to replenish energy reserves. Oxygen Debt = Amount of oxygen needed to restore muscle fiber to pre-exertion conditions. Muscle fibers, liver, sweat glands. (3) Excessive heat is lost via blood flow to skin. Process can take hours to days depending on level of exertion and energy reserves you had to start with.
|
|
What is Power (Force)?
|
Maximum amount of tension produced by a muscle/muscle group.
|
|
What is Endurance?
|
Amount of time a muscle can perform a particular activity.
|
